5-halo-bicyclo{8 2,2,2{9 oct-2-ene-1,4-dicarboxylic acid

ABSTRACT

A new class of 1,4,5 (or 6)-trisubstituted bicyclo(2,2,2)Oct-2ene compounds are prepared by reacting a 1,4-disubstituted 2,3dihydrobenzene with a substituted vinyl compound. The derivatives are polycarboxylic acids, or can be hydrolyzed to polycarboxylic acids, and are suitable for use in condensation polymers such as polyamides and polyesters.

tates atent Pines Aug. 29, 1972 5-HALO-BICYCLO[2,2,21OCT-2-ENE- 1,4-DICARBOXYLIC ACID [72] Inventor: Seemon H. Pines, 24 Candlewood Drive, Murray Hill, NJ. 07974 [22] Filed: March 13, 1969 [21] Appl. No.: 807,082

[52] US. Cl. ..260/468 B, 260/78 UA, 260/78.4 E,

260/464, 260/514 B, 260/544 L, 260/557 B [51] Int. Cl ..C07d 61/28, C07c 69/74 [58] Field of Search ..260/468, 514

[56] References Cited UNITED STATES PATENTS 3,526,657 9/1970 Loeffler ..260/514 OTHER PUBLICATIONS Kaver et al., J.O.C.S. 30 1,431, 1965 Primary ExaminerLorraine A. Weinberger Assistant Examiner-Robert Gerstl Attomey-I. Louis Wolk, Harry E. Westlake, Jr. and Francis H. Deef [57] ABSTRACT 3 Claims, N0 Drawings The present invention relates to a novel and useful class of compounds. More particularly, it relates to the preparation of bicyclo[2,2,2]oct-2-ene compounds which are suitable for use as intermediates.

It is known in the art that 2,3-dihydroterephthalic acid can be reacted with ethylene to give a bicyclo[2,2,2]-ene-l,4-dicarboxylic acid, which compounds are useful in preparing polyesters and polyamides. See U.S. Pat. No. 3,081,334. However, the process is limited to the use of ethylene and the products contain only two substituent groups. It has now been found that by using a substituted vinyl compound a trisubstituted final product is obtained.

It is an object of the present invention to provide a new class of intermediate compounds. A further object is to provide a process for forming such compounds. Another object is to provide intermediates which are polycarboxylic acids or can be converted to polycarboxylic acids which can be utilized in the formation of polyesters and polyamides. A still further object is to provide intermediate products which can be converted into pharmaceutical products. Other objects will become apparent as the description of the invention proceeds.

These objects are accomplished by the present invention which provides compounds of the formula wherein each R is selected from the group consisting of COOR CN, COhalide and CON(R and X is selected from the group consisting of halogen, lower alkoxy, CN, lower alkanoyl, CHO,

which comprises reacting, at a temperature above about 100C., a dihydrobenzene compound of the formula with a vinyl compound of the formula CH CHX wherein each R is selected from the group consisting of COOR, CN, COhalide and CON(R,),; and X is selected from the group consisting of halogen,

lower alkoxy, CN, lower alkanoyl, CHO,

and COOR with each R being H or lower alkyl.

In carrying out the process of the present invention, a solvent is generally not required since many of the reactants are liquids. However, in some instances a solvent is desired and it may be selected at will providing that it is inert to the reactants and stable under the reaction conditions. Such solvents include, without limitation, xylene, diphenyl ether, o-dichlorobenzyl, diethylene glycol diethyl ether, dioxane and the like.

The reaction is generally carried out at a temperature above about C. and below about 280C. although these limits may be varied somewhat. A more preferred temperature range is from about C. to about 220C. depending on the reactants. Most of the reactants react at a temperature of from C. to C. and this temperature is generally employed. The reaction is generally quite slow and may take a few hours to several days to obtain desirable yields. While the reaction may be carried out under any pressure conditions, it is preferred that it be carried out under autogeneous pressure so that none of the reactants are lost. Generally, a sealed bomb type of reactor is used.

Catalysts are not required for the reaction but may be used if desired. In general, Lewis acid catalysts such as boron trifluoride and zinc chloride would be used.

Among the various dihydrobenzene compounds which may be utilized in the practice of the present invention are 1,4-dicarboxy-2,3dihydrobenzene, l,4- dicarbomethoxy-Z,3-dihydrobenzene, l-chlorocarbonyl-4-carbomethoxy-2,3dihydrobenzene, l-carboxamido-4-carbomethoxy-2,3-dihydrobenzene, l-(N- benzyl)carboxamido-4-carbomethoxy-2,3- dihydrobenzene, l ,4-dicarboxamido-2 ,3- dihydrobenzene and the like. The vinyl compounds which may be used include, without limitation, vinyl bromide, vinyl chloride, acrylonitrile, vinyl acetate, acrylamide, methyl acrylate, acrylic acid, acroleinand the like.

The products prepared in accordance with the present invention can be easily hydrolyzed to polycarboxylic acids which are useful in preparing polyamides, i.e. nylons and polyesters, i.e. alkyd resins. The compounds are particularly useful for modifying the properties of the polyamides and polyesters of U.S. Pat. No. 3,081,334 by the replacement of a portion of the acid in the patent with one or more of the acids which can be produced by the present invention. The compounds of the present invention are also useful as plasticizers for natural and synthetic resins, particularly the polyesters and polyamides.

The following examples are given to illustrate the invention and are not intended to limit it in any manner. All parts are given in parts by weight unless otherwise expressed.

EXAMPLE 1 Procedure A 100 Mg. of l,4-dicarbomethoxy-2,3-dihydrobenzene is placed in a heavy-walled glass tube with 5 mg. of hydroquinone (to inhibit polymerization) and 1 ml. of vinyl bromide. The tube is sealed and placed within a protective steel autoclave. The reactants are heated at 180C. for 72 hours and then cooled. The mixture is removed and the excess vinyl bromide is evaporated leaving 1 ,4-dicarbomethoxy-5-bromo-bicyclo[ 2,2,2loct-2-ene. Procedure 8 The product of Procedure A is hydrolyzed by dissolv-' ing 10 millimoles of the product in 50 ml. of ethanol with millimoles of sodium hydroxide. The solution is refluxed for one hour and then acidified to Congo Red with dilute hydrochloric acid. The 5-bromobicyclo[ 2,2,21oct-2-ene-l ,4-dicarboxylic acid crystallizes from solution. It can be used to form polyesters and polyamides as shown in U.S. Pat. No. 3,081,334. Procedure C 10 Millimoles of the product of Procedure A is dissolved in ml. of a mixture of ethanol and l N potassium hydroxide (1:1 ratio) and hydrogenated at psig over 500 mg. of 10 percent Pd. on barium sulfate. When two equivalents of hydrogen have been absorbed, the pressure is released and the catalyst filtered from the solution. The solution is heated at 60C. for an additional hour and then cooled. The solution is then acidified to Congo Red with dilute hydrochloric acid and the product crystallizes therefrom. The product is bicyclo[2,2,2]octane-l,4-dicarboxylic acid. The saturated dicarboxylic acid can also be used to form the polyesters and polyamides of U.S. Pat. No. 3,081,334.

EXAMPLE 2 5 Grams of l,4-dicarbomethoxy-2,3-dihydrobenzene is mixed with 10 ml. of acrolein, 50 mg. of hydroquinone (to inhibit polymerization) and 35 ml. of xylene and placed in a heavy glass tube which is sealed. The mixture is heated in the sealed tube at 170C. for 17 hours. The tube is cooled. The solution remaining in the tube is combined with a chloroform extract of the polymeric residues and chromatographed to give a liquid having the structural formula is I CH2 OHO EXAMPLE 3 pounds are separated by chromatography on silica gel. The final product may be used directly for the forma tion of polyesters and polyamides.

EXAMPLE 4 100 Mg. of l-cyano-4-carbomethoxy-2 ,3- dihydrobenzene is placed in a heavy-walled glass tube with 5 mg. of hydroquinone. The tube and contents are cooled to C. and 3 grams of vinyl chloride are condensed in the tube which is then sealed. The sealed tube is then placed in a protective steel container which is pressurized with nitrogen at 500 psig. The tube is then heated for 48 hours at 170C.. After cooling, the contents of the glass tube are chromatographed on alumina to give a mixture of the two isomers l-cyano-4- carbomethoxy-S-(and 6)-chloro-bicyclo [2,2,2]oct-2- ene.

EXAMPLE 5 The procedure of Example 4 is repeated employing an equivalent amount of l-(N-benzyl)-carboxamido-4- carboxymethyl-Z,3-dihydrobenzene in place of the lcyano-4-carbomethoxy-2,3-dihydrobenzene. After being chromatographed on alumina, the product is a mixture of the compounds l-(N-benzyl)-carboxamido- 4-carbomethoxy-5-(and 6)-chloro-bicyclo[2,2,2]-oct- 2-ene.

EXAMPLE 6 Procedure A The procedure of Example 4 is repeated employing 100 mg. of l,4-di(chlorocarbonyl)-2,3- dihydrobenzene. The final product is l,4-di(chlorocarbonyl)-5-chloro-bicyclo-[2,2,2]oct-2-ene. Procedure B The product from Procedure A can be hydrolyzed by refluxing for 1 hour in 5 ml. of water which is then evaporated to dryness to give l,4-dicarboxy-5-chlorobicyclo[2,2,2]oct-2-ene.

EXAMPLE 7 Procedure A The procedure of Example 2 is repeated employing methyl acrylate rather than acrolein. The resulting product is 1,4,5-tricarbomethoxy-bicyclo[2,2,2]oct-2- ene. Procedure B The product of Procedure A is hydrolyzed by refluxing it with 35 millimoles of sodium hydroxide in 50 ml. of a methanol/water (/20) mixture. After 1 hour at reflux the methanol is removed in vacuo and the residue taken up in water. The solution is acidified with dilute hydrochloric acid to Congo Red to give the product l,4,5-tricarboxy-bicyclo[2,2,2]oct-2-ene. The poly functional acid may be utilized in the formation of alkyd resins.

I claim:

1. Compounds of the formula T1 kT Halogen wherein each R is -COOR with each R being hydrogen or lower alkyl.

2. Compounds of the formula 

2. Compounds of the formula
 3. 1,4-Dicarbomethoxy-5-bromo-bicyclo(2,2,2)oct-2-ene. 